Remove .ruby-version due to https://github.com/twbs/bootstrap/commit/4f20a29c329aa58919919426cbd2190fabfdb723
run grunt
Merge branch 'master' of github.com:twbs/bootstrap
run up-to-date grunt
Indent banner to match the *'s
Merge pull request #10908 from ZDroid/patch-4

Indent banner to match the *'s
Merge pull request #10871 from ZDroid/patch-2

Remove .ruby-version from excludes
run grunt
unify button sizing, use mixin ".button-size" also for the base sized button